Drake R8B VFO adjustment
 

The VFO is a little off and I would like to touch it up.

In CW mode and the 2.4 filter and receiving WWV it is easy to tell that:
5 MHz is spot on
10 MHz is 20 Hz low
15 MHz is 30 Hz low

I haven't been getting the 20 MHz transmission very well so I was
thinking of centering the adjustment on either 10 MHz or 15 MHz.

The synthesizer board is on the bottom of the unit and I don't know what
to adjust. On the bottom board there is a tube type crystal with a cap
trimmer next to it behind the volume control as one possibility and one
of the large metal covered cans has a hole in it for a coil adjustment
in the middle of the side of the bottom board behind the tone control as
another likely place to adjust the main VFO oscillator. The rest are
individual coils that can be adjusted.

If you can clearly indicate which of the many coils or the one cap
trimmer to adjust I would appreciate it.

--
Telamon
Ventura, California

Drake R8B VFO adjustment
 

Telamon wrote:

The VFO is a little off and I would like to touch it up.

In CW mode and the 2.4 filter and receiving WWV it is easy to tell that:
5 MHz is spot on
10 MHz is 20 Hz low
15 MHz is 30 Hz low

I haven't been getting the 20 MHz transmission very well so I was
thinking of centering the adjustment on either 10 MHz or 15 MHz.

The synthesizer board is on the bottom of the unit and I don't know what
to adjust. On the bottom board there is a tube type crystal with a cap
trimmer next to it behind the volume control as one possibility and one
of the large metal covered cans has a hole in it for a coil adjustment
in the middle of the side of the bottom board behind the tone control as
another likely place to adjust the main VFO oscillator. The rest are
individual coils that can be adjusted.

If you can clearly indicate which of the many coils or the one cap
trimmer to adjust I would appreciate it.

If you can't get an answer here you might want to go to http://www.qth.net/ and
sign up to the Drake mailing list and post the question there.

dxAce
Michigan
USA

Drake R8B VFO adjustment
 

In article ,
dxAce wrote:

Telamon wrote:

The VFO is a little off and I would like to touch it up.

In CW mode and the 2.4 filter and receiving WWV it is easy to tell that:
5 MHz is spot on
10 MHz is 20 Hz low
15 MHz is 30 Hz low

I haven't been getting the 20 MHz transmission very well so I was
thinking of centering the adjustment on either 10 MHz or 15 MHz.

The synthesizer board is on the bottom of the unit and I don't know what
to adjust. On the bottom board there is a tube type crystal with a cap
trimmer next to it behind the volume control as one possibility and one
of the large metal covered cans has a hole in it for a coil adjustment
in the middle of the side of the bottom board behind the tone control as
another likely place to adjust the main VFO oscillator. The rest are
individual coils that can be adjusted.

If you can clearly indicate which of the many coils or the one cap
trimmer to adjust I would appreciate it.

If you can't get an answer here you might want to go to
http://www.qth.net/ and sign up to the Drake mailing list and post
the question there.

Thanks for that tip dxAce.

--
Telamon
Ventura, California

Drake R8B VFO adjustment
 

On Sat, 19 Nov 2005 20:14:08 GMT, Telamon
wrote:

In article ,
dxAce wrote:

Telamon wrote:

The VFO is a little off and I would like to touch it up.

In CW mode and the 2.4 filter and receiving WWV it is easy to tell that:
5 MHz is spot on
10 MHz is 20 Hz low
15 MHz is 30 Hz low

I haven't been getting the 20 MHz transmission very well so I was
thinking of centering the adjustment on either 10 MHz or 15 MHz.

The synthesizer board is on the bottom of the unit and I don't know what
to adjust. On the bottom board there is a tube type crystal with a cap
trimmer next to it behind the volume control as one possibility and one
of the large metal covered cans has a hole in it for a coil adjustment
in the middle of the side of the bottom board behind the tone control as
another likely place to adjust the main VFO oscillator. The rest are
individual coils that can be adjusted.

If you can clearly indicate which of the many coils or the one cap
trimmer to adjust I would appreciate it.

If you can't get an answer here you might want to go to
http://www.qth.net/ and sign up to the Drake mailing list and post
the question there.

Thanks for that tip dxAce.
L56 adjusts the 35 Mhz reference oscillator.

Drake R8B VFO adjustment
 

Here is the adjustment point:
http://www.bluegrassdavinci.com/gall...keR8BVFOAdjust

Let the radio warm up for a few hours to get thermally stable, and then
flip upside down, remove the cover and make your adjustment. I
generally adjust for WWV at 10 MHz. You may need a small flashlight to
shine into the adjustment hole to make it easier.

Drake R8B VFO adjustment
 

In article ,
David wrote:

On Sat, 19 Nov 2005 20:14:08 GMT, Telamon
wrote:

In article ,
dxAce wrote:

Telamon wrote:

The VFO is a little off and I would like to touch it up.

In CW mode and the 2.4 filter and receiving WWV it is easy to tell that:
5 MHz is spot on
10 MHz is 20 Hz low
15 MHz is 30 Hz low

I haven't been getting the 20 MHz transmission very well so I was
thinking of centering the adjustment on either 10 MHz or 15 MHz.

The synthesizer board is on the bottom of the unit and I don't know what
to adjust. On the bottom board there is a tube type crystal with a cap
trimmer next to it behind the volume control as one possibility and one
of the large metal covered cans has a hole in it for a coil adjustment
in the middle of the side of the bottom board behind the tone control as
another likely place to adjust the main VFO oscillator. The rest are
individual coils that can be adjusted.

If you can clearly indicate which of the many coils or the one cap
trimmer to adjust I would appreciate it.

If you can't get an answer here you might want to go to
http://www.qth.net/ and sign up to the Drake mailing list and post
the question there.

Thanks for that tip dxAce.
L56 adjusts the 35 Mhz reference oscillator.

I don't have the service information and the circuit board is not
labeled on the component side facing the bottom of the cabinet so can
you indicate, which one of the possible 13 coil adjustments is "L56."

--
Telamon
Ventura, California

Drake R8B VFO adjustment
 

In article .com,
"JerryJ" wrote:

Here is the adjustment point:
http://www.bluegrassdavinci.com/gall...keR8BVFOAdjust

Let the radio warm up for a few hours to get thermally stable, and then
flip upside down, remove the cover and make your adjustment. I
generally adjust for WWV at 10 MHz. You may need a small flashlight to
shine into the adjustment hole to make it easier.

A picture is worth many words. Thank you very much.

--
Telamon
Ventura, California

Drake R8B VFO adjustment
 

On Sat, 19 Nov 2005 21:04:28 GMT, Telamon
wrote:

In article ,
David wrote:

On Sat, 19 Nov 2005 20:14:08 GMT, Telamon
wrote:

In article ,
dxAce wrote:

Telamon wrote:

The VFO is a little off and I would like to touch it up.

In CW mode and the 2.4 filter and receiving WWV it is easy to tell that:
5 MHz is spot on
10 MHz is 20 Hz low
15 MHz is 30 Hz low

I haven't been getting the 20 MHz transmission very well so I was
thinking of centering the adjustment on either 10 MHz or 15 MHz.

The synthesizer board is on the bottom of the unit and I don't know what
to adjust. On the bottom board there is a tube type crystal with a cap
trimmer next to it behind the volume control as one possibility and one
of the large metal covered cans has a hole in it for a coil adjustment
in the middle of the side of the bottom board behind the tone control as
another likely place to adjust the main VFO oscillator. The rest are
individual coils that can be adjusted.

If you can clearly indicate which of the many coils or the one cap
trimmer to adjust I would appreciate it.

If you can't get an answer here you might want to go to
http://www.qth.net/ and sign up to the Drake mailing list and post
the question there.

Thanks for that tip dxAce.
L56 adjusts the 35 Mhz reference oscillator.

I don't have the service information and the circuit board is not
labeled on the component side facing the bottom of the cabinet so can
you indicate, which one of the possible 13 coil adjustments is "L56."

Universal still has some manuals.

http://www.universal-radio.com/catal...2.html#options

Drake R8B VFO adjustment
 

On 19 Nov 2005 13:03:45 -0800, "JerryJ" wrote:

Here is the adjustment point:
http://www.bluegrassdavinci.com/gall...keR8BVFOAdjust

Let the radio warm up for a few hours to get thermally stable, and then
flip upside down, remove the cover and make your adjustment. I
generally adjust for WWV at 10 MHz. You may need a small flashlight to
shine into the adjustment hole to make it easier.

That be it.

Drake R8B VFO adjustment
 

Telamon wrote:
In article .com,
"JerryJ" wrote:

Here is the adjustment point:
http://www.bluegrassdavinci.com/gall...keR8BVFOAdjust

Let the radio warm up for a few hours to get thermally stable, and
then flip upside down, remove the cover and make your adjustment. I
generally adjust for WWV at 10 MHz. You may need a small flashlight
to shine into the adjustment hole to make it easier.

A picture is worth many words. Thank you very much.

Yeah it's pretty easy to do and the trimpot is not that sensitive. The
Drake service manual recommends reading pin 1 of U35 and adjust until it
reads 35.00000 MHz +/- 10 Hz if the receiver has been warmed up for at least
2 hours -or set it to 35.00017 MHz +/- 10 Hz at room temp (if you don't
want to wait). Setting to WWV is, of course, just fine also.

--
Brian Denley
http://home.comcast.net/~b.denley/index.html